Communication system, non-transitory computer-readable medium storing communication program and communication device

A communication device comprising:

• a processor, and
• a memory storing computer-readable instructions, the computer-readable instructions, when executed by the processor, perform processes comprising:
• a first communicating operation communicating from inside a first local area network (LAN) with a conference server via a proxy server to establish a session for a remote conference between the communication device and the conference server using a first proxy setting, the conference server being provided outside the first LAN, the proxy server being provided inside the first LAN, the first proxy setting being stored in a storage device of the communication device and being a setting to communicate via a specific proxy server;
• a first determining operation determining whether establishment of the session has succeeded using the first proxy setting by the first communicating operation;
• a storing operation storing in the storage device, when the determination by the first determining operation that the establishment of the session has succeeded, device information of another communication device in association with specific LAN information as history information, the other communication device participating in the remote conference, the specific LAN information identifying a specific LAN to which the other communication device connects, and the device information being received from the conference server;
• a second determining operation determining, in response to the determination by the first determining operation that the establishment of the session has failed, whether first LAN information identifying the first LAN is included in the history information stored in the storage device;
• a first transmitting operation transmitting directly without the conference server, in response to the determination by the second determining operation that the first LAN information identifying the first LAN is included in the history information, setting request data to a specific communication device identified by device information associated with the first LAN information in the history information, the setting request data being data to request a second proxy setting and being data that includes at least device information of the communication device and identifying the communication device, the second proxy setting being a setting to communicate with the conference server from inside the first LAN via the proxy server;
• a second communication operation communicating, in response to receiving of the second proxy setting from the specific communication device, with the conference server to establish a session for a remote conference between the communication device and the conference server using the received second proxy setting,
• a third determining operation determining whether establishment of the session has succeeded using the second proxy setting by the second communicating operation;
• and
• a second storing operation storing in the storage device, when the determination by the third determining operation that the establishment of the session has succeeded, the device information of the other communication device in association with the first LAN information as history information.

A non-transitory computer-readable medium storing computer-readable instructions, the computer-readable instructions, when executed by a processor of a communication device, perform processes comprising:

• a first communicating operation communicating from inside a first local area network (LAN) with a conference server via a proxy server to establish a session for a remote conference between the communication device and the conference server using a first proxy setting, the conference server being provided outside the first LAN, the proxy server being provided inside the first LAN, the first proxy setting being stored in a storage device of the communication device and being a setting to communicate via a specific proxy server;
• a first determining operation determining whether establishment of the session has succeeded using the first proxy setting by the first communicating operation;
• a first storing operation storing in the storage device, when the determination by the first determining operation that the establishment of the session has succeeded, device information of another communication device in association with specific LAN information as history information, the other communication device participating in the remote conference, the specific LAN information identifying a specific LAN to which the other communication device connects, and the device information being received from the conference server;
• a second determining operation determining, in response to the determination by the first determining operation that the establishment of the session has failed, whether first LAN information identifying the first LAN is included in the history information stored in the storage device;
• a first transmitting operation transmitting directly without the conference server, in response to the determination by the second determining operation that the first LAN information identifying the first LAN is included in the history information, setting request data to a specific communication device identified by device information associated with the first LAN information in the history information, the setting request data being data to request a second proxy setting and being data that includes at least device information of the communication device and identifying the communication device, the second proxy setting being a setting to communicate with the conference server from inside the first LAN via the proxy server;
• a second communication operation communicating, in response to receiving of the second proxy setting from the specific communication device, with the conference server to establish a session for a remote conference between the communication device and the conference server using the second proxy setting,
• a third determining operation determining whether establishment of the session has succeeded using the second proxy setting by the second communicating operation;
• and
• a second storing operation storing in the storage device, when the determination by the third determining operation that the establishment of the session has succeeded, the device information of the other communication device in association with the first LAN information as history information.